Identification of MPO-positive capillaries of the pleura by immunohistochemistry in MPO-ANCA associated vasculitis.

We present a case of a middle-aged woman with myeloperoxidase anti-neutrophil cytoplasmic autoantibody (MPO-ANCA)-associated vasculitis that demonstrated immunohistochemically positive MPO capillaries of the pleura. The patient initially presented with proteinuria and microscopic hematuria at the age of 38. Acute progressive glomerulonephritis and pulmonary hemorrhage occurred 4 years later, and a high serum titer of MPO-ANCA was detected therefore a diagnosis of microscopic polyangiitis was made. Steroid-pulse therapy was performed and the pulmonary shadow improved, but the renal failure did not improve, thus, hemodialysis was initiated. Thereafter, an 18-year asymptomatic phase followed, but high serum levels of MPO-ANCA persisted during this period. Chronic pulmonary hemorrhage was discovered at the age of 60, and video-assisted thoracoscopic surgery was performed. Resected tissue revealed diffuse aloveolar hemorrhage accompanied by marked hemosiderin deposition, whereas MPO-immunopositive capillaries were identified only in the pleura. To our knowledge, this is the first report demonstrating MPO-positive capillaries in a disease other than glomerulonephritis. Judging from this unique case, MPO-positive endothelial cells may appear only during the hyperacute stage before hemorrhage, and may diminish thereafter, thus, may be associated with the trigger of microscopic polyangiitis.

Relationships of nutrient intake and lifestyle-related factors to serum folate and plasma homocysteine concentrations in 30-69 year-old Japanese.

We studied non-hospitalized 30-69 y-old Japanese subjects to ascertain the influences of a 677C-T methylene-tetrahydrofolate reductase (MTHFR) genotype, nutritional intake and lifestyle-related factors on plasma homocysteine (Hcys) and serum folate concentrations. Hcys was higher and serum folate was lower in males than in females (p < .01). The Hcys concentration was higher in the VV group than in the AA and AV groups for both males and females. However, a relatively low serum folate concentration of 18 +/- 7 nmol/L was found in the entire male group as compared with 22 +/- 10 nmol/L in all females. In the female subjects, serum folate concentrations differed among MTHFR genotypes, being lowest in the VV group. In all male subjects, log folate intake per 1,000 kcal was a significant positive predictor of log serum folate concentration (p < 0.01), while in females the log vitamin C intake per standard body weight was a significant positive variable (p < 0.001) predicting the log serum folate concentration. Smokers had significantly lower serum folate concentrations, regardless of dietary folate intake. High folate and vitamin C consumptions, appears to be beneficial to normal and heterozygous MTHFR genotype subjects for maintaining serum folate concentrations. Even a 400 microg daily intake of folate might be less than what is needed, especially for homozygous MTHFR subjects and smokers, to maintain an adequate serum folate concentration.